The emergence of potentially faster-spreading variants of the coronavirus is increasing concern about the virus’s path just as the vaccines that many hope will bring an end to the pandemic are being distributed.
The variant causing the most alarm has been found primarily in southeast England, according to a report from the European Centre for Disease Prevention and Control (ECDC), which has prompted new lockdown restrictions within the United Kingdom and bans on travel from the U.K. to some other countries. By Monday, scattered cases involving this variant had already been detected in several European countries as well as in Canada.
There are no confirmed cases of this variant in the U.S., though Anthony Fauci, MD, director of the National Institute of Allergy and Infectious Diseases, told the PBS Newshour last week that it’s probably here already.
But Fauci also said: “It doesn’t seem at all to have any impact on the virulence or what we call the deadliness of the virus. It doesn’t make people more sick. And it doesn’t seem to have any impact on the protective nature of the vaccines that we’re currently using.”
Beginning Monday, the U.S. will require people arriving here from the United Kingdom by plane to have tested negative by a PCR or antigen test no more than 72 hours before departure.
Infectious disease experts note that viruses always mutate. This virus, like many others, constantly acquires and loses genetic traits as it spreads.
“I would not be surprised of the existence of additional novel strains within the populace, ones that have yet to be identified,” says James Dickerson, PhD, chief scientific officer for Consumer Reports.
Here’s what we know about the variants causing concern now.
Why Do Viruses Mutate?
Viruses like SARS-CoV-2, which causes COVID-19, make imperfect copies of themselves as they spread from person to person or from an animal to a person, leading to constant mutations and new variants, says Peter Katona, MD, an infectious disease specialist and clinical professor of medicine at the David Geffen School of Medicine at UCLA. These mutations often don’t provide any advantage to the virus. But sometimes, a mutation can make a virus more transmissible or change the severity of the disease the virus causes.
How Has the Coronavirus Mutated?
The SARS-CoV-2 virus first emerged in China and continued to mutate as it spread around the globe. A variant that was likely more contagious emerged in Europe, Katona says. That variant’s infectiousness helped it spread rapidly throughout Europe and the U.S., where it became one of the most dominant strains.
The variant under investigation in the U.K. has a large number of mutations, according to the ECDC report, including changes to the spike protein that the coronavirus uses when infecting cells. After comparing the number of coronavirus cases in the U.K. with cases predicted by computer models, scientists there think this variant could be as much as 70 percent more infectious than existing variants.
But people traveling for the holidays could also account for some of the higher case figures. Scientists need more data before they’ll know if this variant is more infectious and to what degree, says Gregory Poland, MD, a professor of medicine and infectious diseases, and director of the Vaccine Research Group at the Mayo Clinic.
There’s no data indicating that this variant of the virus causes people to become sicker.
Where Are Current Mutations Spreading?
Cases of the variant that’s under investigation in the U.K. are primarily in Kent, regions of London, and wider southeast England, according to the ECDC. But this version has also been identified in Wales, Denmark, Belgium, The Netherlands, Australia, Canada, and elsewhere, indicating that it has spread internationally as well.
Other countries, including the U.K., do more routine virus sequencing than the U.S., which makes it difficult to know for sure whether the variant is here yet. (Sequencing is the kind of analysis scientists do to determine the variant of a virus causing a particular case, or a particular outbreak.) Viruses have been sequenced in just 51,000 of the 17 million COVID-19 cases in the U.S., according to the Centers for Disease Control and Prevention (CDC). “Given the small fraction of U.S. infections that have been sequenced, the variant could already be in the United States without having been detected,” the agency noted.
If this variant does prove to be more contagious, however, people should expect it to spread further, Katona and Poland say.
While the large number of mutations in this variant have raised questions about how it emerged, it’s not the only virus variant that scientists are investigating. An evolutionarily distant variant with some similar mutations is spreading rapidly in South Africa, according to the ECDC, which could indicate that mutations like this aren’t uncommon.
How Might Mutations Affect the Vaccine?
Vaccines teach our immune system to respond to a virus by recognizing some key sign of it. Mutations that affect the parts of the virus the immune system recognizes can help a virus thwart a vaccine’s effectiveness.
The first vaccines that have been authorized in the U.S. for COVID-19, made by Moderna and a partnership of Pfizer and BioNTech, target a particular protein—the spike protein—that the coronavirus uses to infect people. So mutations of that protein could potentially make a vaccine less effective, Poland says.
But even if the mutations in current variants of the virus have some impact on the vaccines’ efficacy, it’s likely that the vaccines could still be highly effective, he says.
Still, we may eventually need new vaccines that target other parts of the SARS-CoV-2 virus, Poland wrote in a commentary for the journal Vaccine, where he’s the editor.
What Should You Do?
The same advice about stopping the spread of the virus is even more crucial if this mutation spreads faster. “The appropriate action is caution, follow the existing procedures for mask wearing, social distancing, and minimizing the number of potential lines of exposure,” says CR’s Dickerson.
The more the coronavirus spreads, the more it mutates, according to Poland and Katona.
“We are needlessly prolonging the duration and the severity of this pandemic by not following a simple hands, face, space paradigm,” Poland says.
– Courtesy of Consumer Reports